hwrng: amd - Revert managed API changes

After commit 31b2a73c9c5f ("hwrng: amd - Migrate to managed API"), the
amd-rng driver uses devres with pci_dev->dev to keep track of resources,
but does not actually register a PCI driver.  This results in the
following issues:

1. The message

WARNING: CPU: 2 PID: 621 at drivers/base/dd.c:349 driver_probe_device+0x38c

is output when the i2c_amd756 driver loads and attempts to register a PCI
driver.  The PCI & device subsystems assume that no resources have been
registered for the device, and the WARN_ON() triggers since amd-rng has
already do so.

2.  The driver leaks memory because the driver does not attach to a
device.  The driver only uses the PCI device as a reference.   devm_*()
functions will release resources on driver detach, which the amd-rng
driver will never do.  As a result,

3.  The driver cannot be reloaded because there is always a use of the
ioport and region after the first load of the driver.

Revert the changes made by 31b2a73c9c5f ("hwrng: amd - Migrate to managed
API").

Cc: <stable@vger.kernel.org>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Fixes: 31b2a73c9c5f ("hwrng: amd - Migrate to managed API").
Cc: Matt Mackall <mpm@selenic.com>
Cc: Corentin LABBE <clabbe.montjoie@gmail.com>
Cc: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-geode@lists.infradead.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c
index 4a99ac756f0815a890665f1433b1038a98069be9..9959c762da2f8ec1f5cb0fde48021598f3deecfd 100644 (file)
--- a/drivers/char/hw_random/amd-rng.c
+++ b/drivers/char/hw_random/amd-rng.c
@@ -55,6 +55,7 @@ MODULE_DEVICE_TABLE(pci, pci_tbl);
 struct amd768_priv {
        void __iomem *iobase;
        struct pci_dev *pcidev;
+       u32 pmbase;
 };
 
 static int amd_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait)
@@ -148,33 +149,58 @@ found:
        if (pmbase == 0)
                return -EIO;
 
-       priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+       priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;
 
-       if (!devm_request_region(&pdev->dev, pmbase + PMBASE_OFFSET,
-                               PMBASE_SIZE, DRV_NAME)) {
+       if (!request_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE, DRV_NAME)) {
                dev_err(&pdev->dev, DRV_NAME " region 0x%x already in use!\n",
                        pmbase + 0xF0);
-               return -EBUSY;
+               err = -EBUSY;
+               goto out;
        }
 
-       priv->iobase = devm_ioport_map(&pdev->dev, pmbase + PMBASE_OFFSET,
-                       PMBASE_SIZE);
+       priv->iobase = ioport_map(pmbase + PMBASE_OFFSET, PMBASE_SIZE);
        if (!priv->iobase) {
                pr_err(DRV_NAME "Cannot map ioport\n");
-               return -ENOMEM;
+               err = -EINVAL;
+               goto err_iomap;
        }
 
        amd_rng.priv = (unsigned long)priv;
+       priv->pmbase = pmbase;
        priv->pcidev = pdev;
 
        pr_info(DRV_NAME " detected\n");
-       return devm_hwrng_register(&pdev->dev, &amd_rng);
+       err = hwrng_register(&amd_rng);
+       if (err) {
+               pr_err(DRV_NAME " registering failed (%d)\n", err);
+               goto err_hwrng;
+       }
+       return 0;
+
+err_hwrng:
+       ioport_unmap(priv->iobase);
+err_iomap:
+       release_region(pmbase + PMBASE_OFFSET, PMBASE_SIZE);
+out:
+       kfree(priv);
+       return err;
 }
 
 static void __exit mod_exit(void)
 {
+       struct amd768_priv *priv;
+
+       priv = (struct amd768_priv *)amd_rng.priv;
+
+       hwrng_unregister(&amd_rng);
+
+       ioport_unmap(priv->iobase);
+
+       release_region(priv->pmbase + PMBASE_OFFSET, PMBASE_SIZE);
+
+       kfree(priv);
 }
 
 module_init(mod_init);